Major Issues After Install

[MrSinister55]

Thanks for the links, very informative.
If it still acts up with the cable disconnected, is it going to be any different with the belt off? Keep in mind the engine has to be hot already for the symptoms to start. Something is getting heat soaked and causing the issues. Like I've been saying, it will run flawlessly for 10-20 minutes, then all hell breaks loose. Even last night after letting it cool down for 30 minutes, it started and idled perfectly for about 5 minutes, then the problems began. If I find the alternator is at fault, what do you recommend replacing it with? I'm set up for a one-wire alternator.

[Danny Cabral]

Thanks for the links, very informative.

You're welcome.

If it still acts up with the cable disconnected, is it going to be any different with the belt off?

Yes, because the alternator is still spinning, creating electrical noise.

If I find the alternator is at fault, what do you recommend replacing it with? I'm set up for a one-wire alternator.

Which model alternator is currently on the engine? The CS and/or AD series alternators are the better, more modern types.
Those old school alternators (Ford 1G, 2G/GM 10SI, 12SI, etc.) are very weak at idle, and output a lot of electrical noise.
Modern type alternators (Ford 3G, 4G/GM CS130, CS144, etc.) are much better designs, and output higher amperage at idle RPM.
https://forums.holley.com/showthread...1964#post61964 (Related Forum Post)
https://forums.holley.com/showthread...177#post216177 (Denso Alternator For Mopar Applications)
https://forums.holley.com/showthread...237#post256237 (3G Alternator For Ford Applications)

FYI: It's not safe to run an alternator with the wiring disconnected; remove the alternator belt (safe alternator test).
It's only a momentary test, so the engine won't overheat. Use a shorter water pump belt if you have to.
http://www.pvv.org/~syljua/merc/TooSeptST07.pdf (Alternator AC Ripple Voltage Test)
http://assets.fluke.com/appnotes/aut...e/beatbook.pdf (Fluke Multimeter Testing - Page 3 & 4)
https://forums.holley.com/showthread...0251#post50251 (Related Forum Thread)

[MrSinister55]

No idea what model it is, I got it on Amazon. (The home of all quality parts!) This is the alternator: https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1. Idle output seems sufficient, it stays around 14.2-14.4V. Nothing to do with interference, just stating it seems to be up to the task output-wise. Would this be a good replacement? I've heard Powermaster is top notch: https://smile.amazon.com/Powermaster...ire+alternator. There's definitely something happening in the charging system, as evidenced by the shift light on my tach pulsating in time with the engine running & stumbling. That pulsating lines up perfectly with the glitches on the handheld. The fact that it seems to be getting worse & worse, could point to a diode crapping out. I REALLY want this EFI to work, I'm just getting very, very frustrated.

[81 TransAm]

That alternator looks like a 10SI. That design is very old. I run an AD244. They have a different bolt pattern, but can be made to work with a longer belt. They have two fans in them and put out 145 amps in stock form. They can be found in early 2000s GM trucks & SUVs. You want the 4-pin model not the 2-pin model. The 2-pin model is for computer controlled. You also want the one with the wider case. It has a divider between the front and rear case. The one with the narrower case has less amps, in around the 100 amp range. I picked up a spare from an auto wreckers that works good. This is what one looks like: https://www.summitracing.com/int/par...0347/overview/. You can get them in one wire, but you can trigger it yourself. The 4-pin plug only uses two of the wires. One wire triggers it to turn on and the other wire is a voltage reference wire that goes to the battery. The trigger wire is a resistance wire. It needs to have a resistor in line or you can use a small light bulb. That would be what your idiot light does in your dash.

[MrSinister55]

So that Powermaster I listed above, think that will work? :D
That alternator you listed looks like a PITA to install.

[Danny Cabral]

So that Powermaster I listed above, think that will work?

Yes, that's a much better design alternator.

[MrSinister55]

Yes, that's a much better design alternator.

Thank you. So given my symptoms displayed in the videos I posted, do you think AC noise in the charging system could be the culprit? I'm going to try your test by removing the belt anyway, I'm just looking to confirm my suspicions are plausible. If AC noise is indeed the culprit, is there a chance that it's damaged the Sniper ECU?

[Danny Cabral]

So given my symptoms displayed in the videos I posted, do you think AC noise in the charging system could be the culprit?

I can't answer that question.

I'm going to try your test by removing the belt anyway, I'm just looking to confirm my suspicions are plausible.

Yes, many people are surprised when doing this.

If AC noise is indeed the culprit, is there a chance that it's damaged the Sniper ECU?

No.

[MrSinister55]

Fair enough. Thanks again.

EDIT: I've been reading and researching AC Ripple and its effects on automotive charging systems. The symptoms look an awful lot like mine as reflected in the Sniper & tach. Gonna try the no-belt alternator test, and also the headlight on test with the alternator belt on once symptoms start. If they flicker, that makes three unrelated systems showing the same symptoms. At that point, it almost has to be a bad diode in the alternator. Also, look at my voltage readout on the handheld in the videos, it's NEVER steady, it's always moving around by up to .3 of a volt. I understand it will fluctuate, but it's always all over the place within that .3 of a volt or so. I noticed it was more stable with the cable unhooked from the alternator. If it's a bad diode, I bet that fluctuation will increase over time. My voltmeter gauge is steady at idle & cruise, but will dip in time with the turn signals, when I turn on the headlights, etc. I'm thinking the voltage readout on the Sniper is much more accurate than an analog SunPro gauge.

[Firebob]

6 weeks! Dude you're nowhere near the record. I haven't been able to drive my car since January. If unhooking the charge wire (or the plug), or pulling the belt off from your alternator doesn't make a difference, you have an issue different from mine. It sounds similar, but mine is a drastic difference when in hooking the alternator. I've been through four alternators. Now running a CS130. No change. Good luck.

[MrSinister55]

Well, I didn't even have to try the belt test. I hooked my multimeter up at the battery after symptoms appeared and it was showing loads of AC in the system. I swapped out my cheap alternator for a known good alternator from a buddy's shop. The symptoms have improved and the AC readings on the meter are less, but are still there once it's good & hot. Took an AC reading with it cold and was showing a trace amount of AC in the line. Took one after it showed the first symptoms on the new alternator, and this is what my meter shows: https://www.youtube.com/watch?v=asGAJa8BBIw

It is hotter than the fires of hell under the hood now. It never got this hot before. Maybe I'm baking alternators, I don't know. The back of the alternator is only a couple inches away from the front primary tube, so maybe it's just too much heat. I get no AC in the system when cold, but a ton when hot. I also swapped out my coil for the almost new spare I had as well, as another tech with Holley thinks the coil was to blame, which it doesn't appear to be.

BUT the handheld is not freaking out anymore, nor are all the sensors reading NO DATA when the symptoms start. So something has improved at least. It's got a horrible miss now due to what I think is a burned plug boot, because the resistor plugs are a hair longer than my old non-resistor plugs, and the boot is just touching the primary on the back cylinder on the driver's side. I'm going to have to go back to the old plugs, since they were clearly not the culprit, and throw some more money at this thing to get a new set of plug wires to replace the set that's a year old. I can't win. Thanks to everybody who offered advice, help, or just well wishes.

[BITE_ME]

The rear of the alternator is the input for cooling air.

[Twisted Z]

Glad to see you're getting somewhere!

[MrSinister55]

Sure am, carburetor is back on and the car is running great again. I do not have the time or inclination to keep fighting this thing. Short of rewiring my whole car, I'm out of ideas and I'm not wasting more time or money trying to make this thing work. So I'll make somebody a good deal on a basic Sniper unit (I'm retaining the electric fuel pump setup) and Dual Sync distributor for SBC with maybe 30 miles on them.

[rschid]

Just wondering if you tried just swapping the distributor. I'm still fighting the HyperSpark with timing control. Runs great with the MSD Street Fire.